Key to the species of Barathranthus

1	Young internodes terete; many of the leaves vestigial and deciduous; flowers unisexual, dioecious; corolla less than 8 mm long Barathranthus axanthus
1'	Young internodes 4-angular; leaves all fully developed; flowers hermaphrodite; corolla more than 10 mm long Barathranthus productus